The present invention relates to improvements in plastic reclosable fasteners or zippers with sliders for opening and closing the reclosable fasteners on plastic-film bags and the like and particularly to a detent lock structure for locking the slider in closed position when the slider reaches the fully closed position at the end of its travel along the reclosable fastener.
Plastic zippers with sliders are well known in the art. The plastic zippers have a pair of male and female fastener elements in the form of reclosable interlocking rib and groove elements with a slider having separator structure for opening and closing the rib and groove elements. In the manufacture of plastic-film bags, a pair of these male and female fastener elements extend along the mouth of the bags and these male and female elements are secured in any suitable manner to the flexible walls of the bags. These elements may be integral marginal portions of such walls or they may be extruded separately and thereafter attached to the walls along the mouth of the bag. It frequently is desirable that the plastic-film bags be leakproof. One example of a plastic-film bag having a slider and flexible closure strips adapted to be joined by such slider to form an air-tight closure is disclosed in U.S. Pat. No. 3,259,951--Zimmermann. Another example of a plastic-film bag with a leakproof zipper and slider is disclosed in U.S. Pat. No. 5,020,194--Herrington et al. For leakproof plastic-film bags it also is desirable that the bags include a detent structure for retaining the slider in closed position. Examples of this type construction are disclosed in U.S. Pat. No. --5,067,208 Herrington et al and U.S. Pat. No. 5,189,764--Herrington et al.
Another example of a detent structure is disclosed in our copending patent application entitled "Plastic Reclosable Fastener with Structure for Restraining Slider in Closed Position and for Facilitating Reopening the Fastener" Ser. No. 08/098983, filed Jul. 29, 1993.
It would be desirable to provide a plastic-film bag with a zipper that is operated by a slider wherein a detent lock using spring-loaded elements is provided on the slider to lock the slider in closed position when the slider reaches the fully closed position at the end of its travel along the zipper.